DE UGARTE POSTIGO , Antonio

Gamma-ray bursts (GRBs) are beginning to be regularly detected by ground-based Cherenkov telescopes at the TeV range. Although the number of detections is still small, it is expected to grow dramatically as the new telescopes of the CTA observatories come online. It has been discussed that the local environment in which the explosion is...

The gamma-ray burst of the ninth of October of 2022 (GRB 221009A) was the brightest ever recorded. It saturated most of the gamma-ray detectors in space and even affected the Earths ionosphere. On ground, Cherenkov detectors measured photons of up to 18 TeV, never seen before for these objects. It's brightness allowed amateur telescopes to...

EIFIS (Extreme Integral FIeld Spectrograph) is a modular integral field spectrograph, based on image slicers, and makes use of new, large format detectors. The concept is thought to cover the largest possible field of view while producing spectroscopy over the complete optical range (3 000 - 10 000 Å) at a medium resolving power of about 2400....

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Ultra-long gamma-ray bursts (ULGRBs) are characterized by exceptionally long-duration central engine activities, with characteristic timescales exceeding 1000 seconds. We present ground-based optical afterglow observations of the ultra-long gamma-ray burst GRB 211024B, detected by \textit{Swift}. Its X-ray light curve exhibits a characteristic...

Gamma-ray bursts (GRBs) are the most luminous transients in the universe and are utilized as probes of early stars, gravitational wave counterparts, and collisionless shock physics. In spite of studies on polarimetry of GRBs in individual wavelengths that characterized intriguing properties of prompt emission and afterglow, no coordinated...

Core-collapse supernovae are explosions of massive stars at the end of their evolution. They are responsible for metal production and for halting star formation, having a significant impact on galaxy evolution. The details of these processes depend on the nature of supernova progenitors, but it is unclear if Type Ic supernovae (without hydrogen...

Early optical observations of gamma-ray bursts can significantly contribute to the study of the central engine and physical processes therein. However, of the thousands observed so far, still only a few have data at optical wavelengths in the first minutes after the onset of the prompt emission. Here we report on GRB 190106A, whose afterglow...

High-redshift gamma-ray bursts (GRBs) provide a powerful tool to probe the early universe, but still for relatively few do we have good observations of the afterglow. We here report the optical and near-infrared observations of the afterglow of a relatively high-redshift event, GRB 220101A, triggered on New Year's Day of 2022. With the optical...